function Item(x, y, width, height, color, activity, visible){
	this._activity = activity;
	this._color = color;
	this._visible = visible;
	Item.superclass.constructor.call(this, x, y, width, height);
	this.draw = function(context){
		context.fillStyle = color;
		context.beginPath();
		context.rect(this._x, this._y, this._width, this._height);
		context.closePath();
		context.fill();
	}
}
extend(Item, Unit)
var items = new Array();
items.push(new Item(0,0,50,50, "red", true, true));
items.push(new Item(0,100,50,50, "red",true, true));
items.push(new Item(100,0,50,50, "blue",true, true));
items.push(new Item(200,300,50,50, "black",true, true));